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Topic Review (Newest First)

08-17-2011 08:23 PM

cool rockin daddy

6 year old post, Speed.

08-17-2011 07:22 PM

SPEED MASTERS CC

YOU ARE RIGHT ON! THE 106 LCA WILL BE GREAT!

Quote:

Originally Posted by 454C10

I would run 11:1 cr with a cam that big. I have no problems with my 350 with 11:1 and a big cam with pump gas. And I have iron heads and I run N20. Big cams bleed off cylinder pressure! Don't confuse compression ratio with cylinder pressure.

Plus long rods, short strokes, and big cams can handle a bunch of compression ratio on pump gas.

Tight lobe centers makes a lopey idle and a shorter and peaker power band and quicker throttle response. The opposite is true for wider lobe centers. Overlap doesn't bleed off cylinder pressure!!!! It is the late closing point of the intake valve that causes that. As the piston is rising in the cylinder bore (on the compression stroke), if the intake valve is still open it reduces cylinder pressure (makes sense). Furthermore, wider lobe centers will cause the intake valve to close later which will cause reduced pressure. But, it ALL depends on the intake closing point.

327's make about the same hp as a 350 but need more rpm to do it. Plus 327's make less torque makes of a shorter stoke (less mechanical advantage).

Your cylinder heads will be the limiting factor. I'm guessing 425 hp at 7000 rpm and 400 ft lb of torque at 4800 rpm with a 10.5 cr 327.

03-26-2005 07:56 AM

NAIRB

Quote:

Originally Posted by J327HO

"sorry about putting this in someone elses thread,I am ...

..
hello boys...me and my brother are having a 67' 327 built ...here's whats going into it...

... anyways ...if im missing something just tell me,lol... what would the horsepower potential be for this setup we're doing here??? the block work was donr by Jungle, it is .60 over ...everything was checked,crank is great! ...anyways,like to know the power potential we'll have with this... Thanks!!!

oh,we might go with a Holley street avenger 770 carb,just depends....and the engine is going to be balanced by a race shop close to here....everyone swears by them and there work.. so..

You are building a racing engine. I assume you are going to use racing fuel. Personally, if you are just building a toy, you might as well bump the compression up to about 12.5:1.

Forget running pump fuel in it anyway. Bite the bullet and buy some race gas. You need the big compression ratio to increase torque. Everything else looks fine for a drag motor. Use very deep gears and a high RPM launch.

03-25-2005 11:51 PM

wshinn

Quote:

Originally Posted by 454C10

Changing to a cam with a wider lobe center (like 110) would reduce the dynamic compression and lessen the octane requirement.

It seems to me that a wider lobe center-line angle (LCA) would reduce overlap between the intake and exhaust valve opening, effectively increasing the dynamic compression and increasing the octane requirement. A narrower LCA cam would increase overlap, decrease the dynamic compression ratio, and give you "a better shot" at running pump gas with the iron heads and the 11:1 compression ratio.

The narrow LCA cam will also decrease manifold vacuum (vs. a wider LCA cam), idle rougher, and make optimum torque and HP at higher RPM. Going with the narrow LCA cam almost necessitates you running a little higher static compression to have adequate "dynamic compression" with a camshaft that has alot of overlap. An overlap of 50 to 75 degrees is about the maximum for a "hot" street rod setup and... as a general rule... the smaller engine displacement requires wider LCAs. I did not see an LCA for the cam listed in your post, but a LCA of around 110 degrees would be worth considering in your build up with a 280 duration camshaft.

02-09-2005 08:01 AM

454C10

Even a 9:1 engine could detonate on pump gas if the cam was small enough!

Look into calculating the "dynamic compression ratio" of your engine combo. This formula uses stroke, rod length, static compression, and intake closure point to find the "real" compression ratio. Do a web search on dynamic compression ratio and you will find a bunch of stuff.

Changing to a cam with a wider lobe center (like 110) would reduce the dynamic compression and lessen the octane requirement. The wider lobe center moves out the intake closure point.

good luck!

02-08-2005 05:33 PM

1964chevelle

i think it is 11:1 thanks for the information

02-08-2005 08:41 AM

454C10

I would run 11:1 cr with a cam that big. I have no problems with my 350 with 11:1 and a big cam with pump gas. And I have iron heads and I run N20. Big cams bleed off cylinder pressure! Don't confuse compression ratio with cylinder pressure.

Plus long rods, short strokes, and big cams can handle a bunch of compression ratio on pump gas.

Tight lobe centers makes a lopey idle and a shorter and peaker power band and quicker throttle response. The opposite is true for wider lobe centers. Overlap doesn't bleed off cylinder pressure!!!! It is the late closing point of the intake valve that causes that. As the piston is rising in the cylinder bore (on the compression stroke), if the intake valve is still open it reduces cylinder pressure (makes sense). Furthermore, wider lobe centers will cause the intake valve to close later which will cause reduced pressure. But, it ALL depends on the intake closing point.

327's make about the same hp as a 350 but need more rpm to do it. Plus 327's make less torque makes of a shorter stoke (less mechanical advantage).

Your cylinder heads will be the limiting factor. I'm guessing 425 hp at 7000 rpm and 400 ft lb of torque at 4800 rpm with a 10.5 cr 327.

02-07-2005 11:25 PM

firestone

1964 your combo sounds good. I cant see anything wrong with it. My best guess would be around 330 hp assuming you are at around 9.5:1 compression.

Adam

02-07-2005 09:44 PM

1964chevelle

327

im building one also for my chevelle it is out of a 64 vette and has 461 double hump heads 234/244 .488.510 600 cfm performer carb and performer rpm intake. headers crane 1.6:1 roller rockers i was wondering what kind of power i would be making?

i also have a 3500 stall and a turbo 350 with a stage 2 shift kit...any other suggestions?

02-07-2005 09:40 PM

firestone

I would actually consider the Performer RPM air gap. It is rated to 6500 RPM, but on a 327 it will probably pull close to 7000 RPM. The 700 carb sounds good. If you changed your intake, I think a 3200-3500 stall would work well. You have 200cc runner heads right?

Oddrodder, it looks like we are pretty much on the same page with this one.

OR Weiand team G power ram intake - power range - 2,800-7,200 ... and a classic holley 700 double pumper...would these help out for alittle bit of street manners without sacrificing my top end around 6,500-7000RPM ??? ....

well...i've gotta altleast thank all of you for your replies,and yes they were VERY helpful to me...if anyone has anything to say or see's something *wrong* with this build,please tell me! lol....alot of money is gonna be spent on everything for this and just want it to be worth it!! THANKS AGAIN!!!

02-07-2005 07:54 PM

OddRodder

Yeah, I'm sure I can use it. I found a pretty bad crack in a different cylinder than the one we were lookin' at! Hope it doesn't take 2 sleeves!! I'll try to get a pic. of it in a minute or two! Checked out the video tried to make out the roadsign three or four times, I think I could read 412.

02-07-2005 07:47 PM

NXS

Well the graph may not be that great, but the vid should load. Keep in mind this is a V6 with welded spiders. I held it kind of straight until the end. It got a bit sideways just before it stopped spinning. I figure that sign is about 1/8 mile from my driveway.
So, will that block work for you? I hope so b/c that was a long ways to drive for a cracked block, lol!

02-07-2005 07:33 PM

OddRodder

Hey NXS, your graph is a comparion of say a 106 to 112 LSA? It leaves a little to the imagination! I tried to watch your rainy day video a while ago but it wouldn't load for some reason? Think I'll go try again!!

02-07-2005 07:20 PM

NXS

Ok, i re-read. OP said 106 C and Oddrodder said 106 lobe sep!

Your lobe sep determines how power is distributed in the rpm range. A tight sep makes for a less efficient engine with power being concentrated in the mid and mid-upper rpm ranges. It will allow for more compression as it bleed off pressure from valve overlap.
A wide lobe sep on the other hand is more efficient but builds a lot of cylinder pressure and is better suited for lower compression daily drivers (or highway rockets). They will provide a smoother idle with more initial response and more topend power but will result in lower peak numbers due to their wide power band.

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